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Biochar: Hope for the world

To examine the strange material ‘Biochar’ and its place in ‘saving the planet’.

by James Lamont

Suitable for Key Stage 4/5


To examine the strange material ‘Biochar’ and its place in ‘saving the planet’.

Preparation and materials


  1. Begin by asking the students, have any of them heard of ‘biochar’? Any guesses as to what it might be?
  2. As the world moves on from last December’s Copenhagen climate change conference, opinions differ on the best way to deal with the problem of greenhouse gases and pollution. Some people advocate a carbon tax, or an exchange mechanism to provide pollution permits. Others do not think that this will work, and look to technology to solve the problem.
  3. Such technologies include artificial trees to capture carbon from the atmosphere, or new forms of energy such as solar power and geothermal energy. An increasingly exciting option is called ‘biochar’. If it works, biochar has the advantage of providing energy and reducing the overall amount of carbon dioxide in the atmosphere. In addition, it could boost world food output. With the world looking upwards, with grandiose projects like enormous solar panels in space or sulphuring the sky, advocates of biochar look down to the ground. Biochar is a form of soil.
  4. If sewage is burnt it often causes large carbon output. The biochar process sounds like a modern piece of magic: it ‘burns’ sewage and produces energy and heat, which can be sold and used to heat homes or commercial premises, and also produces a waste product – charcoal. Charcoal is useful because it retains carbon – up to 60% of the potential carbon in the sewage. Owing to the fact that the burnt plant products in the sewage took in carbon and sent out oxygen, the whole process is ‘carbon-negative’ – less carbon is in the atmosphere than at the start of the process. Ta-da! Less carbon than at the beginning – as I said, it sounds almost like a modern piece of magic.
  5. The charcoal can store carbon for around 1,000 years. It is mixed with soil to produce biochar itself, which is a soil that is more effective for growing crops, thus making a contribution to a world with an increasing population and inadequate food supplies.
  6. Biochar is a good example of technology which can substantially aid humanity as a whole, but it needs cultivating. The main advantage – the carbon storage aspect – currently lacks financial incentives. If there were a clear financial gain in storing carbon, then big business could latch onto the project, bringing in money and political clout.
  7. But no matter what the success of biochar, it is not a miracle cure for all our ills. Even if it can allow the human race to postpone climate change, the world will still have many problems, many caused by the same unjust economic and political structures that had a defining role in causing climate change. Unless we can change these structures of domination, we will always be looking for miracle cures to our modern carbon-emitting lifestyles.

Time for reflection

Light a candle and play some reflective music. Give time for the students to settle.

I wonder how you feel about global warming, and the whole question of our personal carbon footprint?

Will you use public transport rather than asking your family or friends for lifts by car?

Will you fly off to the sun this year?

Will you eat less meat as a way of cutting your own carbon footprint?

Will you choose not to buy the latest fashion clothing, and so reduce waste?

Will you use a jute bag when you go shopping?

Small steps along the way to changing how we live.

Some small steps on the way to saving the planet.

Continue to play the music as students leave the assembly.

Publication date: February 2010   (Vol.12 No.2)    Published by SPCK, London, UK.
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